$A$ photoelectric surface is illuminated successively by monochromatic light of wavelength $\lambda$ and $\lambda /2$. If the maximum kinetic energy of the emitted photoelectrons in the second case is $3$ times that in the first case,the work function of the surface of the material is
$(h =$ Planck's constant,$c =$ speed of light $)$

When the wavelength of radiation falling on a metal is changed from $500 \, nm$ to $200 \, nm$,the maximum kinetic energy of the photoelectrons becomes three times larger. The work function of the metal is close to $..... \, eV$.

When a metal surface is illuminated by light of wavelengths $400\; nm$ and $250\; nm$,the maximum velocities of the photoelectrons ejected are $v$ and $2v$ respectively. The work function of the metal is ($h =$ Planck's constant,$c =$ velocity of light in air).

Statement $1$: $A$ metal surface is irradiated by monochromatic light of frequency $v > v_0$. The maximum kinetic energy and stopping potential are $K_{max}$ and $V_0$ respectively. If the frequency of the incident light is doubled, then $K_{max}$ and $V_0$ will also be doubled. Statement $2$: The stopping potential and maximum kinetic energy of photoelectrons emitted from a surface depend linearly on the frequency of the incident light.

When a metallic surface is illuminated with radiation of wavelength $\lambda$,the stopping potential is $V$. If the same surface is illuminated with radiation of wavelength $3 \lambda$,the stopping potential is $V/4$. The threshold wavelength for the metallic surface is.

How does the maximum kinetic energy of a photoelectron depend on the frequency of incident radiation? On which factors does it not depend?